Analytical screw design technology
1 screw compressor will become popular
11 screw compressor reputation changed from bad
In the past, screw compressors have been considered to be high in noise, high in fuel consumption, and high in power consumption, and are at a disadvantage in competition with piston compressors. Now due to the continuous improvement of screw profile design research and the improvement of equipment processing precision, the identification test of screw air compressor shows that the specific power can reach 48 kW/(m3 /min), which can reach the maximum energy consumption of fixed air compressor. Good level; the noise of closed screw air compressor can reach 60~85dB(A); the foreign screw compressor has no fault operation for more than 710h, and some even exceed 1010h. The domestic screw compressor life can reach 410h, tail gas residual oil Low content.
Development of 12 screw design calculation system
The development of the screw design calculation system has completed the rotor profile calculation, geometric property calculation, thermal performance prediction, rotor force analysis, rotor deformation calculation, and blade shape calculation. The SCCAD screw compressor design and calculation software developed by Professor Xing Ziwen of Xi'an Jiaotong University has been transferred to Taiwan Fusheng Co., Ltd., Wuxi Compressor Factory, Wuhan Refrigeration Plant, Yantai Refrigerator Factory and many other domestic and overseas enterprises.
SCCAD software has also had an impact in the international arena. Carrier has signed two international cooperation agreements with the research group of Xi'an Jiaotong University. The aim is to use SCCAD software to conduct more in-depth theoretical research and experimental analysis of the company's products.
At present, there are fixed injection screw air compressors LG-6/ 7, LG-10/7, LG-20/10 in China; air-cooled mobile oil-injected screw compressors LGY-17/7, LGY-12 /7 type; lightweight injection screw air compressor QLG10-3/10 type; micro injection screw air compressor LG -12/7 type; and oil-free screw chlorine compressor LG75 type, oil-free screw nitrogen compressor LG130 type. A total of 7 models of the 3rd generation screw refrigeration compressor LG16~LG25 have been certified.
13 screw compressor heat is also shown in the joint venture
D&B, the largest screw compressor manufacturer in the United States, is a joint venture partner with Yantai Refrigerator Factory.
TR Company and Jiangyin Lithium Bromide Refrigerator Factory jointly established Shuangliang Trane Company.
YO company built a factory in Wuxi, Guangzhou.
Ca company established a factory in Shanghai and Tianjin.
Shanghai Compressor Factory and Ingersoll Rand of the United States jointly produce screw air compressors with a production capacity of 6000 pairs/year screw rotor. Joint venture with the American Dresserland to produce a process screw compressor.
Screw heat of 14 compressor plant
In 1985, Wuxi Compressor Factory only had 1 ZAC milling machine. In 1995, it was equipped with 2 5AC milling machines. The screw production capacity reached 12,000 pairs/year.
Among them, ductile iron screw rotors account for a large proportion.
Nanjing Compressor Factory is the enterprise that invested in the most screw manufacturing equipment since 1995. In 1995, there was only one QHz-029 semi-automatic spiral rotor milling machine of Qinghai Machine Tool Plant. In 1996, it imported a HNC35SL full CNC high-precision grinding machine from Germany Klingelub erg. Up to 8000 pairs / year.
Liuzhou Fidelity Machinery Co., Ltd. imported one screw grinding machine from Italy SU Company.
Jiangxi Gas Compressor Factory, Yantai Air Compressor Factory, Nanjing Sanda Machinery Co., Ltd., Beijing First General Machinery Factory, Tianjin Huabei Air Compressor Factory and Ningbo Xinda Screw Compressor Co., Ltd. all produce screw air compressors. Zhongshan Fusheng Electromechanical Co., Ltd., Shenyang Air Compressor Factory, Dalian Air Compressor Factory, etc. purchased screw assembly screw air compressor. Chongqing Air Compressor Factory produces 20m3 /min screw air compressor, and its screw rotor is supplied by Chongqing Jialing Refrigeration and Air Conditioning Equipment Co., Ltd. Zizhong Petroleum Machinery Factory cooperates with Xi'an Jiaotong University to produce screw compressors for oil and gas fields.
15 foreign screw processing equipment factory
Germany Klingeluberg Company, Hermle Company, Italy Saporiti and SU Company, UK Holroyd Company, Maerix Company, etc. all set up offices in China, agency, business activities are very active. In order to win the user, not only the manufacturing equipment but also the design and manufacture of the screw line of the product, the equipment can be put into production screw as soon as the equipment arrives.
16 screw compressor market share
Screw compressors account for more than 80% of the mobile air compressor market in foreign countries. The domestic market has a small share due to diesel engines, and only foreign products occupy less market. Screw air compressors account for 85% of the total screw compressors. Screw compressors account for about 12% of refrigeration and air conditioning.
Development of screw tooth shape of 17 screw compressor
The first generation is the Lysholm tooth profile, and the main line segment consists of a point-type cycloid, which is limited to the oil-free screw compressors used in the current processing conditions.
The second generation is the symmetrical circular tooth profile of 1964, 4+6 teeth, and the main line segment consists of an arc and an arc envelope that meshes with it. Power screw compressors are the main application targets.
The third generation is an asymmetric toothed SRM, 4+6 teeth. The main line segment consists of point-like cycloid and arc envelope, which is 10% more efficient than the second generation. It is widely used for fuel injection and oil-free screw. compressor.
The fourth generation, after 1982, represented by the SRM-D tooth profile, 5+6 teeth, 4+5 teeth, and the main line segments of 5+7 teeth are line-like curves with no sharp points. SRM introduces the D-tooth shape and believes that it is not a specific tooth shape, but a comprehensive software package for computerized calculation of the optimal tooth shape depending on the application. The performance requirements, reliability, longevity, economical rotor material and manufacturing method of different applications are considered. The fourth-generation tooth profile should also include the tooth profile with the above characteristics applied or developed by the world-renowned screw compressor company during this period. All fourth-generation tooth profiles are energy-saving.
2 single screw compressor
The single screw compressor was invented and developed by Zimmern. Due to its superior durability and reliability, it is suitable for medium and large capacity compressors. The twin-screw compressor was invented in 1934, the single-screw compressor was invented in 1960, and the first prototype was produced in 1962. It consists of a screw and two (or one) two-sided (or one) star wheels. At the beginning of the invention, the single screw was expected to be too high. It is considered to have all the advantages of twin screw without the double screw. The efficiency can be increased by 5~7% compared with the twin screw. However, after 20 years, the single screw has not been developed rapidly. There are only 4 to 5 screw manufacturers. Japan Daikin (DA) and Mitsubishi (ME), British Hall and the United States Vzlter, the Dutch GR company originally produced a single screw to produce twin screw. China's air compressor and refrigeration industry have been discontinued after trial production.
Single screw development time is short, structure and materials are still under discussion. For example, the star wheel wears and energy decreases, the suction and exhaust passages are narrow, the resistance loss is large, and the leakage between the high and low pressure chambers makes the efficiency not higher than the twin screw. However, its vibration and noise are low, so the semi-closed screw compressor, which is the main engine of the chiller, has been developed in the past 10 years. The single-screw compressor with the largest cooling capacity reaches 350kW.
3 design and manufacturing technology of plastic mechanical screw
Professor Liu Tinghua from Sichuan University gave a report on the characteristics and technical development of screw design in plastic machinery. In terms of screw manufacturing technology, it is unanimously considered that the current hardening of the screw after milling and sand belt polishing is the most backward process; after the screw quenching, the press is straight, and then there is no finishing process, and the residual stress is released under 300 working conditions. The screw is re-bending, and the screw is scraped by the screw during operation, thereby accelerating the wear of the screw and the barrel. It is not desirable to accelerate the screw and the barrel during the screw process; the screw is not bent vertically during the storage of the finished product, causing the screw to bend and reduce the quality of use; The manufacturing of the screw should be processed after forging; the intrinsic quality and dimensional accuracy of the screw have no effective inspection means, which is not conducive to improving the processing quality of the plastic machine.
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